Hi all, I mistakenly applied a vacuum on my DIY line set for my 36k unit. I got the unit to fire work but the cooling is not as it should. My temp gun reads 76 degrees blowing out of the indoor unit. Can someone point me in the right direction to a noob friendly guide to fix my situation? I have access to a pump, gauges and r410a. Thanks you
MrCool 36k install failure ADVISE needed
- Thread starter DIY G
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Jim greengo
Well-known member
Were the lines precharged?
Kaizen
Well-known member
The pipes are sealed so I’m guessing you connected them and then for some reason vacuumed the system?? What were you thinking. I’d Call a pro to vacuum and charge it at this point.
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Yes
No pro will come out to my location, I'm in this alone or with the help you guys.
Not the entire system. I applied a vacuum after connecting the lineset but before releasing the freon from the outdoor unit.
I just need to know how much freon to add back in to the system to replace what came with the lineset.
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SALIV8
Well-known member
Have you reached out to Mr Cool yet?
Terry D
Well-known member
It could be a multiple of things. How long did you vac it down. Did you pull it to 350 microns. Did you close the valves on the gauges and did it hold a vacuum. If you have non condensables in there, like air, it will not perform right. If you released that Freon in that line set with a leak, then your losing your charge. Do you know how to read gauges. they will tell you what is going on.
I just re read your post. Didn't realize this is a diy system. As long as you did not get air in there, you just might have to add Freon. If it is a expansion valve system, you have to charge by sub cooling. It should be listed on the unit somewhere. usually around 10 or 12 degrees. There are tons of stuff on you tube that will help you. Main thing, if you think you got air in there. You need to do a complete vac down and start over.
I just re read your post. Didn't realize this is a diy system. As long as you did not get air in there, you just might have to add Freon. If it is a expansion valve system, you have to charge by sub cooling. It should be listed on the unit somewhere. usually around 10 or 12 degrees. There are tons of stuff on you tube that will help you. Main thing, if you think you got air in there. You need to do a complete vac down and start over.
Kaizen
Well-known member
I’m not a pro either but made sure I followed the instructions perfectly. Guessing you got confused watching non diy install videos.
I don’t remember if the unit actually has Freon. It should be listed someplace how much it held. Thought just lines had it.
Things to verify.
Is it in cool mode?
What was ambient temp when you took reading?
You took all packing material out of fan area?
You coiled extra line set?
How long did you run and was any part of lineset icing up?
Look for a kink
Make sure it was in ac mode not heat or dry mode
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I don’t remember if the unit actually has Freon. It should be listed someplace how much it held. Thought just lines had it.
Things to verify.
Is it in cool mode?
What was ambient temp when you took reading?
You took all packing material out of fan area?
You coiled extra line set?
How long did you run and was any part of lineset icing up?
Look for a kink
Make sure it was in ac mode not heat or dry mode
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I have not seen the latest Mr. Cool ... How are they doing the compressor fitting?
My understanding of the process. The line and head are evacuated -- not charged with refrigerant. They use a standard compressor and simply attach the DIY fitting -- the typical compressor will do 25' with the refrigerant in it. The head unit is fitted with the quick fittings at the factory and evacuated -- same with the lines. So when you get it all attached and before you open the valves it's the same as if you had done a conventional flared setup.
Now, the newest may be different because you can buy different length line set and connect them together ... there has to be some way to make that work. Maybe some long line sets have extra charge ? ... They can't be unboxing and adding to the outside unit. Some still only supply the 25' line.
I would call them ask -- my guess is you are Ok and can just open the valves
My understanding of the process. The line and head are evacuated -- not charged with refrigerant. They use a standard compressor and simply attach the DIY fitting -- the typical compressor will do 25' with the refrigerant in it. The head unit is fitted with the quick fittings at the factory and evacuated -- same with the lines. So when you get it all attached and before you open the valves it's the same as if you had done a conventional flared setup.
Now, the newest may be different because you can buy different length line set and connect them together ... there has to be some way to make that work. Maybe some long line sets have extra charge ? ... They can't be unboxing and adding to the outside unit. Some still only supply the 25' line.
I would call them ask -- my guess is you are Ok and can just open the valves
Terry D
Well-known member
I believe he already opened the valves according to post #5
bazar01
Well-known member
The lineset and indoor unit when you connected to the outdoor unit should only have ambient air inside them and applying vacuum before releasing the refrigerant is the correct procedure to remove air and moisture. You did not do anything wrong. There should be no refrigerant in the lineset and no need to add.
mike93lx
ALLIANCE MEMBER
That isn't now a precharged setup works. No vacuum is required. Plug and play
Terry D
Well-known member
Yep. A DIY unit does not need to vacuumed down. Hook it up and go. That is why they cost about 500 dollars mor than a professional install unit.
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I did and it took them 2 days to call me back. I just got off the phone with them and the tech said I needed to add 13oz of freon back in.
I pulled a vacuum down with my Robinair 3cfm pump for 30 minutes until it wouldnt go any lower. I closed the manifold valves and it held steady for another 30 minutes before I realeased the freon. I dont know how to properly read the gauge but It held steady in the negative.
I'll start watching videos on sub cooling. I have access to a 25lb tank of r410a so I'm not opposed to emptying and refilling but hoping I can learn how to just add the missing freon first. Ill start watching subcooling videos thanks.
I followed the procedure for a non did unit.
Cool mode? yes
Ambient temp? 81 inside, did measure outside but it was probably 85-90. There is constant heat generated inside since this is in a server room.
Lineset came connected to the indoor unit. My gauge read positive pressure prior to vacuuming the system. Quick connect fittings with o-rings. Tech said 13oz needs to added back.
Yes
Thats what I thought and its what lead me down this path but now I know the indoor unit and lineset was precharged.
Followed the wrong youtube video.
Did the Guy at Mr Cool understand that no refrigerant was lost?
Reading your post this was the case --- you did all the pump down and then opened the valves .... but, everything in the compressor stayed in the lines? no leaks.
It was my understanding that the line set was evacuated ..maybe they pressurize it with some refrigerant ... but the compressors come with supplied refrigerant for 25'. Like any other mini ...
If I am wrong and they remove some from the compressor and add to the line set ... they would know. don't know why they would do it that way.
The way they tell you to fix a mini with any loss of refrigerant is to pump it down and weigh in the whole charge.
What's the full charge for the unit? Charging a mini is different -- not the same as a typical split
Reading your post this was the case --- you did all the pump down and then opened the valves .... but, everything in the compressor stayed in the lines? no leaks.
It was my understanding that the line set was evacuated ..maybe they pressurize it with some refrigerant ... but the compressors come with supplied refrigerant for 25'. Like any other mini ...
If I am wrong and they remove some from the compressor and add to the line set ... they would know. don't know why they would do it that way.
The way they tell you to fix a mini with any loss of refrigerant is to pump it down and weigh in the whole charge.
What's the full charge for the unit? Charging a mini is different -- not the same as a typical split
Rusty Fords
Well-known member
It is required by law for anyone using/handling refrigerant to obtain a EPA refrigerant handling lic.
enough of that. The manufactures get around this by providing plug and play units since if someone was to follow the installation instructions you wont have to worry about things like this happening. You tube can teach us a lot about all kinds of things but you need to make sure you got the same equipment or attachments. I've worked in the HVAC trade for 26 plus years ALL compression fittings leak eventually. The ductless units I've installed have flare fittings when done correctly last a long time which the line set and the indoor head have to be evacuated before opening the valves on the outdoor unit.
On the units name tag it will say what the system charge is that amount will be for the outdoor unit, indoor unit, and so many feet of line set. Since you don't know what you currently have for a charge the correct way would be to remove all the remaining charge evacuate the system down and hold below 500 microns valve it of make sure it holds for 15 min and then put the correct amount of new refrigerant into the unit.
enough of that. The manufactures get around this by providing plug and play units since if someone was to follow the installation instructions you wont have to worry about things like this happening. You tube can teach us a lot about all kinds of things but you need to make sure you got the same equipment or attachments. I've worked in the HVAC trade for 26 plus years ALL compression fittings leak eventually. The ductless units I've installed have flare fittings when done correctly last a long time which the line set and the indoor head have to be evacuated before opening the valves on the outdoor unit. On the units name tag it will say what the system charge is that amount will be for the outdoor unit, indoor unit, and so many feet of line set. Since you don't know what you currently have for a charge the correct way would be to remove all the remaining charge evacuate the system down and hold below 500 microns valve it of make sure it holds for 15 min and then put the correct amount of new refrigerant into the unit.
Terry D
Well-known member
Agreed. This is the only way to be sure. Especially if you some how got air in the system. You need to do a full evacuation including the condensor since you opened the service valves.
Plus, if you are going to charge it by sub cooling, you will need a digital thermometer that clamps on the high side line in addition to your gauges. If you know the exact amount of charge, and can access a Freon scale, you could just weigh the charge in. Also, 410a needs to be put in as a liquid, the tank is upside down, it has to be feathered in slowly so not to flood the compressor. They make a charge adaptor that goes on your gauges to prevent this.
https://www.amazon.com/dp/B004RIDG02/?tag=atomicindus08-20
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